Gtk.IMContext¶

Subclasses:: Gtk.IMContextSimple, Gtk.IMMulticontext

Methods¶

Inherited:: GObject.Object (37)
Structs:: GObject.ObjectClass (5)

	`delete_surrounding` (offset, n_chars)
	`filter_key` (press, surface, device, time, keycode, state, group)
	`filter_keypress` (event)
	`focus_in` ()
	`focus_out` ()
	`get_preedit_string` ()
	`get_surrounding` ()
	`get_surrounding_with_selection` ()
	`reset` ()
	`set_client_widget` (widget)
	`set_cursor_location` (area)
	`set_surrounding` (text, len, cursor_index)
	`set_surrounding_with_selection` (text, len, cursor_index, anchor_index)
	`set_use_preedit` (use_preedit)

Virtual Methods¶

Inherited:: GObject.Object (7)

	`do_activate_osk` ()
	`do_commit` (str)
	`do_delete_surrounding` (offset, n_chars)
	`do_filter_keypress` (event)
	`do_focus_in` ()
	`do_focus_out` ()
	`do_get_preedit_string` ()
	`do_get_surrounding` ()
	`do_get_surrounding_with_selection` ()
	`do_preedit_changed` ()
	`do_preedit_end` ()
	`do_preedit_start` ()
	`do_reset` ()
	`do_retrieve_surrounding` ()
	`do_set_client_widget` (widget)
	`do_set_cursor_location` (area)
	`do_set_surrounding` (text, len, cursor_index)
	`do_set_surrounding_with_selection` (text, len, cursor_index, anchor_index)
	`do_set_use_preedit` (use_preedit)

Properties¶

Name	Type	Flags	Short Description
`input-hints`	`Gtk.InputHints`	r/w/en
`input-purpose`	`Gtk.InputPurpose`	r/w/en

Signals¶

Inherited:: GObject.Object (1)

Name	Short Description
`commit`	The `::commit` signal is emitted when a complete input sequence has been entered by the user.
`delete-surrounding`	The `::delete-surrounding` signal is emitted when the input method needs to delete all or part of the context surrounding the cursor.
`preedit-changed`	The `::preedit-changed` signal is emitted whenever the preedit sequence currently being entered has changed.
`preedit-end`	The `::preedit-end` signal is emitted when a preediting sequence has been completed or canceled.
`preedit-start`	The `::preedit-start` signal is emitted when a new preediting sequence starts.
`retrieve-surrounding`	The `::retrieve-surrounding` signal is emitted when the input method requires the context surrounding the cursor.

Fields¶

Inherited:: GObject.Object (1)

Name	Type	Access	Description
parent_instance	`GObject.Object`	r

Class Details¶

class Gtk.IMContext(**kwargs)¶

Bases:: GObject.Object
Abstract:: Yes
Structure:: Gtk.IMContextClass

GtkIMContext defines the interface for GTK input methods.

GtkIMContext is used by GTK text input widgets like GtkText to map from key events to Unicode character strings.

An input method may consume multiple key events in sequence before finally outputting the composed result. This is called *preediting*, and an input method may provide feedback about this process by displaying the intermediate composition states as preedit text. To do so, the GtkIMContext will emit [signal`Gtk`.IMContext::preedit-start], [signal`Gtk`.IMContext::preedit-changed] and [signal`Gtk`.IMContext::preedit-end] signals.

For instance, the built-in GTK input method [class`Gtk`.IMContextSimple] implements the input of arbitrary Unicode code points by holding down the <kbd>Control</kbd> and <kbd>Shift</kbd> keys and then typing <kbd>u</kbd> followed by the hexadecimal digits of the code point. When releasing the <kbd>Control</kbd> and <kbd>Shift</kbd> keys, preediting ends and the character is inserted as text. For example,

Ctrl+Shift+u 2 0 A C

results in the € sign.

Additional input methods can be made available for use by GTK widgets as loadable modules. An input method module is a small shared library which provides a GIOExtension for the extension point named “gtk-im-module”.

To connect a widget to the users preferred input method, you should use [class`Gtk`.IMMulticontext].

delete_surrounding(offset, n_chars)[source]¶

Parameters:

offset (int) – offset from cursor position in chars; a negative value means start before the cursor.
n_chars (int) – number of characters to delete.

Returns:

True if the signal was handled.

Return type:

bool

Asks the widget that the input context is attached to delete characters around the cursor position by emitting the ::delete_surrounding signal.

Note that offset and n_chars are in characters not in bytes which differs from the usage other places in GtkIMContext.

In order to use this function, you should first call [method`Gtk`.IMContext.get_surrounding] to get the current context, and call this function immediately afterwards to make sure that you know what you are deleting. You should also account for the fact that even if the signal was handled, the input context might not have deleted all the characters that were requested to be deleted.

This function is used by an input method that wants to make substitutions in the existing text in response to new input. It is not useful for applications.

filter_key(press, surface, device, time, keycode, state, group)[source]¶

Parameters:

press (bool) – whether to forward a key press or release event
surface (Gdk.Surface) – the surface the event is for
device (Gdk.Device) – the device that the event is for
time (int) – the timestamp for the event
keycode (int) – the keycode for the event
state (Gdk.ModifierType) – modifier state for the event
group (int) – the active keyboard group for the event

Returns:

True if the input method handled the key event.

Return type:

bool

Allow an input method to forward key press and release events to another input method without necessarily having a GdkEvent available.

filter_keypress(event)[source]¶

Parameters:: event (Gdk.Event) – the key event
Returns:: True if the input method handled the key event.
Return type:: bool

Allow an input method to internally handle key press and release events.

If this function returns True, then no further processing should be done for this key event.

focus_in()[source]¶

Notify the input method that the widget to which this input context corresponds has gained focus.

The input method may, for example, change the displayed feedback to reflect this change.

focus_out()[source]¶

Notify the input method that the widget to which this input context corresponds has lost focus.

The input method may, for example, change the displayed feedback or reset the contexts state to reflect this change.

get_preedit_string()[source]¶

Returns:

str:: location to store the retrieved string. The string retrieved must be freed with GLib.free().
attrs:: location to store the retrieved attribute list. When you are done with this list, you must unreference it with [method`Pango`.AttrList.unref].
cursor_pos:: location to store position of cursor (in characters) within the preedit string.

Return type:

(str: str, attrs: Pango.AttrList, cursor_pos: int)

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string.

This string should be displayed inserted at the insertion point.

get_surrounding()[source]¶

Returns:

None if no surrounding text was provided; otherwise a tuple containing:

text:: text holding context around the insertion point.
cursor_index:: byte index of the insertion cursor within text

Return type:

(text: str, cursor_index: int) or None

Retrieves context around the insertion point.

Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

This function is implemented by emitting the [signal`Gtk`.IMContext::retrieve-surrounding] signal on the input method; in response to this signal, a widget should provide as much context as is available, up to an entire paragraph, by calling [method`Gtk`.IMContext.set_surrounding].

Note that there is no obligation for a widget to respond to the ::retrieve-surrounding signal, so input methods must be prepared to function without context.

Deprecated since version 4.2: Use [method`Gtk`.IMContext.get_surrounding_with_selection] instead.

get_surrounding_with_selection()[source]¶

Returns:

TRUE if surrounding text was provided; in this case you must free the result stored in text.

text:: location to store a UTF-8 encoded string of text holding context around the insertion point. If the function returns True, then you must free the result stored in this location with GLib.free().
cursor_index:: location to store byte index of the insertion cursor within text.
anchor_index:: location to store byte index of the selection bound within text

Return type:

(bool, text: str, cursor_index: int, anchor_index: int)

Retrieves context around the insertion point.

Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

This function is implemented by emitting the [signal`Gtk`.IMContext::retrieve-surrounding] signal on the input method; in response to this signal, a widget should provide as much context as is available, up to an entire paragraph, by calling [method`Gtk`.IMContext.set_surrounding_with_selection].

Note that there is no obligation for a widget to respond to the ::retrieve-surrounding signal, so input methods must be prepared to function without context.

New in version 4.2.

reset()[source]¶

Notify the input method that a change such as a change in cursor position has been made.

This will typically cause the input method to clear the preedit state.

set_client_widget(widget)[source]¶

Parameters:: widget (Gtk.Widget or None) – the client widget. This may be None to indicate that the previous client widget no longer exists.

Set the client widget for the input context.

This is the GtkWidget holding the input focus. This widget is used in order to correctly position status windows, and may also be used for purposes internal to the input method.

set_cursor_location(area)[source]¶

Parameters:: area (Gdk.Rectangle) – new location

Notify the input method that a change in cursor position has been made.

The location is relative to the client widget.

set_surrounding(text, len, cursor_index)[source]¶

Parameters:

text (str) – text surrounding the insertion point, as UTF-8. the preedit string should not be included within text
len (int) – the length of text, or -1 if text is nul-terminated
cursor_index (int) – the byte index of the insertion cursor within text.

Sets surrounding context around the insertion point and preedit string.

This function is expected to be called in response to the [signal`Gtk`.IMContext::retrieve-surrounding] signal, and will likely have no effect if called at other times.

Deprecated since version 4.2: Use [method`Gtk`.IMContext.set_surrounding_with_selection] instead

set_surrounding_with_selection(text, len, cursor_index, anchor_index)[source]¶

Parameters:

text (str) – text surrounding the insertion point, as UTF-8. the preedit string should not be included within text
len (int) – the length of text, or -1 if text is nul-terminated
cursor_index (int) – the byte index of the insertion cursor within text
anchor_index (int) – the byte index of the selection bound within text

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the [signal`Gtk`.IMContext::retrieve_surrounding] signal, and will likely have no effect if called at other times.

New in version 4.2.

set_use_preedit(use_preedit)[source]¶

Parameters:: use_preedit (bool) – whether the IM context should use the preedit string.

Sets whether the IM context should use the preedit string to display feedback.

If use_preedit is False (default is True), then the IM context may use some other method to display feedback, such as displaying it in a child of the root window.

do_activate_osk() virtual¶

do_commit(str) virtual¶

Parameters:: str (str) –

Default handler of the [signal`Gtk`.IMContext::commit] signal.

do_delete_surrounding(offset, n_chars) virtual¶

Parameters:

offset (int) – offset from cursor position in chars; a negative value means start before the cursor.
n_chars (int) – number of characters to delete.

Returns:

True if the signal was handled.

Return type:

bool

Asks the widget that the input context is attached to delete characters around the cursor position by emitting the ::delete_surrounding signal.

Note that offset and n_chars are in characters not in bytes which differs from the usage other places in GtkIMContext.

In order to use this function, you should first call [method`Gtk`.IMContext.get_surrounding] to get the current context, and call this function immediately afterwards to make sure that you know what you are deleting. You should also account for the fact that even if the signal was handled, the input context might not have deleted all the characters that were requested to be deleted.

This function is used by an input method that wants to make substitutions in the existing text in response to new input. It is not useful for applications.

do_filter_keypress(event) virtual¶

Parameters:: event (Gdk.Event) – the key event
Returns:: True if the input method handled the key event.
Return type:: bool

Allow an input method to internally handle key press and release events.

If this function returns True, then no further processing should be done for this key event.

do_focus_in() virtual¶

Notify the input method that the widget to which this input context corresponds has gained focus.

The input method may, for example, change the displayed feedback to reflect this change.

do_focus_out() virtual¶

Notify the input method that the widget to which this input context corresponds has lost focus.

The input method may, for example, change the displayed feedback or reset the contexts state to reflect this change.

do_get_preedit_string() virtual¶

Returns:

str:: location to store the retrieved string. The string retrieved must be freed with GLib.free().
attrs:: location to store the retrieved attribute list. When you are done with this list, you must unreference it with [method`Pango`.AttrList.unref].
cursor_pos:: location to store position of cursor (in characters) within the preedit string.

Return type:

(str: str, attrs: Pango.AttrList, cursor_pos: int)

Retrieve the current preedit string for the input context, and a list of attributes to apply to the string.

This string should be displayed inserted at the insertion point.

do_get_surrounding() virtual¶

Returns:

TRUE if surrounding text was provided; in this case you must free the result stored in text.

text:: location to store a UTF-8 encoded string of text holding context around the insertion point. If the function returns True, then you must free the result stored in this location with GLib.free().
cursor_index:: location to store byte index of the insertion cursor within text.

Return type:

(bool, text: str, cursor_index: int)

Retrieves context around the insertion point.

Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

This function is implemented by emitting the [signal`Gtk`.IMContext::retrieve-surrounding] signal on the input method; in response to this signal, a widget should provide as much context as is available, up to an entire paragraph, by calling [method`Gtk`.IMContext.set_surrounding].

Note that there is no obligation for a widget to respond to the ::retrieve-surrounding signal, so input methods must be prepared to function without context.

Deprecated since version 4.2: Use [method`Gtk`.IMContext.get_surrounding_with_selection] instead.

do_get_surrounding_with_selection() virtual¶

Returns:

TRUE if surrounding text was provided; in this case you must free the result stored in text.

text:: location to store a UTF-8 encoded string of text holding context around the insertion point. If the function returns True, then you must free the result stored in this location with GLib.free().
cursor_index:: location to store byte index of the insertion cursor within text.
anchor_index:: location to store byte index of the selection bound within text

Return type:

(bool, text: str, cursor_index: int, anchor_index: int)

Retrieves context around the insertion point.

Input methods typically want context in order to constrain input text based on existing text; this is important for languages such as Thai where only some sequences of characters are allowed.

This function is implemented by emitting the [signal`Gtk`.IMContext::retrieve-surrounding] signal on the input method; in response to this signal, a widget should provide as much context as is available, up to an entire paragraph, by calling [method`Gtk`.IMContext.set_surrounding_with_selection].

Note that there is no obligation for a widget to respond to the ::retrieve-surrounding signal, so input methods must be prepared to function without context.

New in version 4.2.

do_preedit_changed() virtual¶: Default handler of the [signal`Gtk`.IMContext::preedit-changed] signal.

do_preedit_end() virtual¶: Default handler of the [signal`Gtk`.IMContext::preedit-end] signal.

do_preedit_start() virtual¶: Default handler of the [signal`Gtk`.IMContext::preedit-start] signal.

do_reset() virtual¶

Notify the input method that a change such as a change in cursor position has been made.

This will typically cause the input method to clear the preedit state.

do_retrieve_surrounding() virtual¶

Return type:: bool

Default handler of the [signal`Gtk`.IMContext::retrieve-surrounding] signal.

do_set_client_widget(widget) virtual¶

Parameters:: widget (Gtk.Widget or None) – the client widget. This may be None to indicate that the previous client widget no longer exists.

Set the client widget for the input context.

This is the GtkWidget holding the input focus. This widget is used in order to correctly position status windows, and may also be used for purposes internal to the input method.

do_set_cursor_location(area) virtual¶

Parameters:: area (Gdk.Rectangle) – new location

Notify the input method that a change in cursor position has been made.

The location is relative to the client widget.

do_set_surrounding(text, len, cursor_index) virtual¶

Parameters:

text (str) – text surrounding the insertion point, as UTF-8. the preedit string should not be included within text
len (int) – the length of text, or -1 if text is nul-terminated
cursor_index (int) – the byte index of the insertion cursor within text.

Sets surrounding context around the insertion point and preedit string.

This function is expected to be called in response to the [signal`Gtk`.IMContext::retrieve-surrounding] signal, and will likely have no effect if called at other times.

Deprecated since version 4.2: Use [method`Gtk`.IMContext.set_surrounding_with_selection] instead

do_set_surrounding_with_selection(text, len, cursor_index, anchor_index) virtual¶

Parameters:

text (str) – text surrounding the insertion point, as UTF-8. the preedit string should not be included within text
len (int) – the length of text, or -1 if text is nul-terminated
cursor_index (int) – the byte index of the insertion cursor within text
anchor_index (int) – the byte index of the selection bound within text

Sets surrounding context around the insertion point and preedit string. This function is expected to be called in response to the [signal`Gtk`.IMContext::retrieve_surrounding] signal, and will likely have no effect if called at other times.

New in version 4.2.

do_set_use_preedit(use_preedit) virtual¶

Parameters:: use_preedit (bool) – whether the IM context should use the preedit string.

Sets whether the IM context should use the preedit string to display feedback.

If use_preedit is False (default is True), then the IM context may use some other method to display feedback, such as displaying it in a child of the root window.

Signal Details¶

Gtk.IMContext.signals.commit(i_m_context, str)¶

Signal Name:

commit

Flags:

RUN_LAST

Parameters:

i_m_context (Gtk.IMContext) – The object which received the signal
str (str) – the completed character(s) entered by the user

The ::commit signal is emitted when a complete input sequence has been entered by the user.

If the commit comes after a preediting sequence, the ::commit signal is emitted after ::preedit-end.

This can be a single character immediately after a key press or the final result of preediting.

Gtk.IMContext.signals.delete_surrounding(i_m_context, offset, n_chars)¶

Signal Name:

delete-surrounding

Flags:

RUN_LAST

Parameters:

i_m_context (Gtk.IMContext) – The object which received the signal
offset (int) – the character offset from the cursor position of the text to be deleted. A negative value indicates a position before the cursor.
n_chars (int) – the number of characters to be deleted

Returns:

True if the signal was handled.

Return type:

bool

The ::delete-surrounding signal is emitted when the input method needs to delete all or part of the context surrounding the cursor.

Gtk.IMContext.signals.preedit_changed(i_m_context)¶

Signal Name:: preedit-changed
Flags:: RUN_LAST
Parameters:: i_m_context (Gtk.IMContext) – The object which received the signal

The ::preedit-changed signal is emitted whenever the preedit sequence currently being entered has changed.

It is also emitted at the end of a preedit sequence, in which case [method`Gtk`.IMContext.get_preedit_string] returns the empty string.

Gtk.IMContext.signals.preedit_end(i_m_context)¶

Signal Name:: preedit-end
Flags:: RUN_LAST
Parameters:: i_m_context (Gtk.IMContext) – The object which received the signal

The ::preedit-end signal is emitted when a preediting sequence has been completed or canceled.

Gtk.IMContext.signals.preedit_start(i_m_context)¶

Signal Name:: preedit-start
Flags:: RUN_LAST
Parameters:: i_m_context (Gtk.IMContext) – The object which received the signal

The ::preedit-start signal is emitted when a new preediting sequence starts.

Gtk.IMContext.signals.retrieve_surrounding(i_m_context)¶

Signal Name:: retrieve-surrounding
Flags:: RUN_LAST
Parameters:: i_m_context (Gtk.IMContext) – The object which received the signal
Returns:: True if the signal was handled.
Return type:: bool

The ::retrieve-surrounding signal is emitted when the input method requires the context surrounding the cursor.

The callback should set the input method surrounding context by calling the [method`Gtk`.IMContext.set_surrounding] method.

Property Details¶

Gtk.IMContext.props.input_hints¶

Name:: input-hints
Type:: Gtk.InputHints
Default Value:: Gtk.InputHints.NONE
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

Additional hints that allow input methods to fine-tune their behaviour.

Gtk.IMContext.props.input_purpose¶

Name:: input-purpose
Type:: Gtk.InputPurpose
Default Value:: Gtk.InputPurpose.FREE_FORM
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

The purpose of the text field that the `:obj:Gtk.IMContext is connected to.

This property can be used by on-screen keyboards and other input methods to adjust their behaviour.